This invention relates to the field of juice extractors, and more particularly, this invention relates to a juice extractor having an orifice tube moveable within a strainer tube.
A well known juice extractor design is disclosed in U.S. Pat. No. 2,649,730 to Hait, and assigned to the present assignee, the disclosure which is hereby incorporated by reference in its entirety. In this type of vertically arranged juice extractor, upper and lower cups support a fruit, vegetable or similar product. The sides of both upper and lower cups have fingers that intermesh and interdigitate together. The upper cup descends into the lower cup against the fruit or vegetable and is pressed against a circular, lower cutter positioned at the top of a strainer tube adjacent the lower cup and an upper cutter positioned in the upper cup. Plugs are cut into the top and bottom portions of the fruit or vegetable as the interdigitating fingers of the two cups mesh together. Inner portions of the fruit, such as the pulp and juice, are forced down into the strainer tube positioned within a manifold. An orifice tube moves upward in the strainer tube and applies pressure into the internal portion of the strainer tube to separate juice and pulp within the strainer tube.
In some orifice tubes, xe2x80x9cwindowsxe2x80x9d are formed in the orifice tube end that engages the fruit or vegetable for enhancing juice recovery from any pulp. Although this xe2x80x9cwindow tubexe2x80x9d type orifice tube provides enhanced juice recovery, the open areas formed by the xe2x80x9cwindowsxe2x80x9d weaken that end of the orifice tube. Therefore, in one proposed design, a two-piece orifice tube was used where a first tube portion corresponding to the lower orifice tube section received a shorter length, opposing second tube portion, which engaged the fruit or vegetable. This shorter piece was formed from a strong material, such as an alloy tool steel. The two pieces were press fit together to ensure concentricity. Because there was not a strong interface between the parts, the parts would occasionally separate in the field, causing machine damage. The press fit was considered essential because the two pieces of the orifice tube had to be concentric. This was essential because the orifice tube moved within the strainer tube and had to have a clear, concentric clearance to separate juice and pulp within the strainer tube.
It is therefore an object of the present invention to provide a two-piece orifice tube where the tube portion that engages a fruit or vegetable maintains concentricity and engagement with the tube portion forming the orifice tube while maintaining a strong interface between the two pieces.
It is yet another object of the present invention to provide a two-piece orifice tube where the tube portion that engages a fruit or vegetable can be disengaged for replacement from an opposing tube portion.
The present invention is advantageous and provides a juice extractor with a strainer tube mounted to receive juice and pulp of fruit and an orifice tube moveable within the strainer tube. The orifice tube includes a first tube portion and an opposing second tube portion threaded within the first tube portion. A drive mechanism engages the orifice tube and reciprocates the orifice tube within the strainer tube for separating juice and pulp within the strainer tube. The second tube portion has open window areas for enhancing juice recovery from pulp. A close tolerance shank is formed on the second tube portion and received within the first tube portion to guide the second tube portion therein. This second tube portion is formed primarily from hardened tool steel, while the first tube portion is formed primarily from stainless steel.
In yet another aspect of the present invention, the first tube portion includes an internal stop. The second tube portion includes an external stop formed at an end thereof for engaging the internal stop of the first tube portion. This external stop is formed as a shank and is received with a close tolerance fit into the internal stop.